Neuro-muscular Junctions and Muscle Contraction

Neuro-muscular Junctions and Muscle Contraction

Learning Objectives:

• describe the roles of neuromuscular junctions, transverse system tubules and sarcoplasmic reticulum in stimulating contraction in striated muscle;

• describe the ultrastructure of striated muscle with particular reference to sarcomere structure

• explain how a muscle contracts;

• explain how oxygen debt develops and how a muscle may become fatigued.

Sarcolemma

• the plasma membrane of the muscle cell and is surrounded by basement membrane and endomysial connective tissue

• an excitable membrane and shares many properties with the neuronal cell membrane

Sarcoplasmic reticulum

• a membrane-bound structure found within muscle cells that is similar to the smooth endoplasmic reticulum in other cells.

Multiple Select

Which of the following are specialized functional properties of skeletal muscle?

• Irrititability

• Contractility

• Extensibility

• Elasticity

Multiple Choice

The association site of the axon terminal of the motor neuron and sarcolemma of a muscle is called a ...

• synaptic cleft

• neuromuscular junction

• motor end plate

• neurotranmitter

Multiple Select

Graded responses can be produced by changing...

• frequency of muscle contraction

• number of muscle cells being stimulated at one time

• duration of muscle contraction

Multiple Choice

Which of these is a twitch?

Multiple Choice

True or False: Muscle fiber contraction is "all of none".

• True

• False

Multiple Choice

What is the fastest way to generate ATP?

• Direct phosphorylation of ADP by Creatine Phosphate

• Anaerobic glycolysis and lactic acid formation

• Aerobic respiration

Multiple Choice

Which requires oxygen?

• Direct phosphorylation of ADP by Creatine Phosphate

• Anaerobic glycolysis and lactic acid formation

• Aerobic respiration

Multiple Select

Which of the following are causes of muscle fatigue

• ionic imbalances

• lactic acid accumulation in muscle

• decrease in ATP supply

• too much calcium

Poll

I can explain how a muscle contracts.

• 0 - Clueless

• 1 - Basic Knowledge - Need some tutoring

• 2 - Advanced Knowledge - Can apply it

• 3 - Expert - Can tutor others

Poll

I can explain how oxygen debt develops and how a muscle may become fatigued.

• 0 - Clueless

• 1 - Basic Knowledge - Need some tutoring

• 2 - Advanced Knowledge - Can apply it

• 3 - Expert - Can tutor others